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Beyond the Camera - Batteries
Batteries fall into two basic types: rechargeable and disposable. All cameras use either a proprietary lithium-ion rechargeable battery or standard AA type batteries. Lithium-ion batteries carry the most charge and many cameras can take over 500 pictures on an individual charge.
Some compact cameras use standard AA type batteries (most take 2, a few require 4). Although these are readily available, you will not get as many pictures from a set before they need to be replaced. Therefore, although alkaline batteries will work, they are not a cost effective option. Invest in a few good sets of NiMH (Nickel Metal Hydride) rechargeables and they will pay for themselves in a matter of months.
The major disadvantage of NiMh batteries is that they have a very high self discharge rate. What this means is that they gradually discharge themselves even when not in use. All batteries do this to some extent, although NiMH can lose around 30% of their charge each month. Look at this table to see what this means for a fairly modern set of AA batteries (2700mAh)
| Full charged |
2700 mAh |
| After 1 month |
1890 mAh |
| After 3 months |
926 mAh (lost two-thirds of their charge) |
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After 6 months |
318 mAh (basically dead) |
| After 1 year |
completely dead - won't power on the camera |
What this basically means is that there's little point charging up 3 or 4 sets of these in one go. If you are going out taking pictures and want to carry a few spare sets, it pays to have an ultra fast charger and give them a quick top up charge if they have been sitting around for more than a few weeks.
Some companies have developed a new technology NiMH which have much slower self-discharge rates (a loss in charge of around 1 to 2% per month). Because of this, they usually come full charged and ready to use, however they can be charged in any normal NiMH charger. They don't have as high a capacity to start with (usually around 2100mAh, but given that a normal NiMH will be less than that after one month - this should not cause too much concern).
There doesn't seem to be a special name for this technology, so just look out for phrases like "comes ready charged" and "slow self-discharge" on the packaging. Brands to look out for are:
- Sanyo Eneloop
- Panasonic Infinium
- Uniross Hybrio.
Lithium batteries (such as the Energizer Ultimate Lithium) are disposable batteries that can last a lot longer than alkaline. They are also very light and have a long shelf life, however they are very expensive. We would recommend these if you want to keep a spare set of batteries in your camera bag at all time as the shelf life runs into years (not just a few months like NiMH rechargeables).
Do not use cheap non-alkaline batteries in a digital camera. The will last a few as 10 shots and may not even power on the camera due to the high drain put on them by a flash and LCD screen. The same applies to NiCd (Nickel Cadmium) rechargeables - you would be doing well to get 10 shots from these.
Comparison Chart
Shelf life refers to for disposable, how long they can expect to remain good after purchase, and for rechargeables, how long the can retain their charge if not used.
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Units: mAh
On rechargeable batteries, you will often see a figure like 2800mAh. This is an indication of the capacity of a fully charged battery. It means that (in theory at least) a battery can supply that amount of charge for a period of 1 hour before being completely dead. For example, a 2800mAh battery can supply:
2800mA for 1 hour
1400mA for 2 hours
400mA for 7 hours etc.
If you camera take 2 or 4 batteries it does not mean the battery life increases by 2 or 4 times. The extra batteries just increase the overall voltage.
Modern AA batteries have capacities of approaching 3000mAh. |
Battery chargers
There are lots of different types of battery chargers out there - the main difference being the speed at which they can recharge a set of batteries.
A typical charger for AA batteries will charge a set between 15 minutes and 15 hours. So why would you go for anything other than the 15 minute charger?
Batteries continuously charged on ultra fast chargers tend to have a much shorter life (a few hundred charges rather than a thousand). The fast chargers are also more expensive. They also often have problems working with older and lower capacity NiMH batteries.
Our advice, got for a fast but not the fastest charger, learn to plan ahead, and with the money you save, buy a couple of extra sets of batteries. |
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Photographs
This is a site about photography so I'm sure you are expecting to see plenty of pictures.
For now, why not take a peek at the flickr galleries belonging to the two authors of this site.
Colin's Flickr Page
Phil's Flickr Page
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